<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div><span id="zwchr" data-marker="__DIVIDER__">----- On Mar 26, 2020, at 1:39 PM, lttng-dev <lttng-dev@lists.lttng.org> wrote:<br></span></div><div data-marker="__QUOTED_TEXT__"><blockquote style="border-left:2px solid #1010FF;margin-left:5px;padding-left:5px;color:#000;font-weight:normal;font-style:normal;text-decoration:none;font-family:Helvetica,Arial,sans-serif;font-size:12pt;"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div>Hello!</div><br><div>Currently, callstack collection in LTTng is only available for kernel-space events with context fields <i>callstack-kernel </i>and <i>callstack-user</i>.</div><br><div>Is it expected that callstack collection for LTTng-UST will be added too? And if it is expected, then how soon?</div></div></div></div></div></blockquote><div><br></div><div><div>Hi Valentin,<br></div><div><br></div><div>It is something that would be interesting and useful, but a lot of work would</div><div>be needed to have stack-walking this is fast enough and reentrant wrt signal</div><div>handlers. Unfortunately, the backtrace(3) functions do not meet those</div><div>requirements.</div><div><br></div><div>Also, for gathering user-space callstacks from the kernel tracer, it only works if</div><div>all user-space is compiled with frame pointers. This is also a limitation that would</div><div>require a lot of work to overcome neatly.</div><div><br></div><div>None of those features are currently on any roadmap due to lack of customers</div><div>showing interest in getting this done.</div><div><br></div><div>Thanks,</div><div><br></div><div>Mathieu</div></div></div><div><br data-mce-bogus="1"></div><div data-marker="__SIG_POST__">-- <br></div><div>Mathieu Desnoyers<br>EfficiOS Inc.<br>http://www.efficios.com</div></div></body></html>